The goal of this study is to characterize and define the pattern of expression of Egr-3 in brain neurons following both acute and chronic stimulation. The rapid activation of transcription factor genes induced by physiological or pharmacological stimulation is thought to play a key role in mediating changes In gene expression underlying stimulus-induced neuronal plasticity. Accordingly, in this study there will be a comparison of expression of Egr-3 and Egr-1 (also called Zif268, NGFI-A, krox-24) mRNA and protein following acute and chronic stimulus paradigms. The delayed onset bands observed in gel-shift studies that bind to the Zif268 response element will be characterized to determine if they represent Egr-3. Lastly, a detailed analysis will be undertaken to determine the functional differences between the two isoforms of Egr-3.